Microbial pathogenesis
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Microbial pathogenesis · Feb 2018
Diversity of virulence genes in multidrug resistant Pseudomonas aeruginosa isolated from burn wound infections.
Multidrug resistant Pseudomonas aeruginosa has frequently been reported as the cause of nosocomial outbreaks of burn wound infections. The pathogenesis of P. aeruginosa is partly due to the production of several cell-associated and extracellular virulence factors. A total of 93 P. aeruginosa isolated from burn wound infections were investigated for antimicrobial susceptibility and distribution of virulence genes. ⋯ All MDR isolates carried at least 5 virulence factors. These results indicate a high frequency and heterogeneity of virulence gene profiles among multidrug resistant P. aeruginosa isolates recovered from burn wound infections. Therefore, appropriate surveillance and control measures are essential to prevent the further spread of these isolates in hospitals.
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Microbial pathogenesis · Feb 2018
Antibacterial activity and virtual screening by molecular docking of lycorine from Pancratium foetidum Pom (Moroccan endemic Amaryllidaceae).
Lycorine is an alkaloid isolated from bulbs of Pancratium foetidum Pom Amaryllidaceae of the genus Lycoris. It has very strong pharmacodynamics properties and biological effects, among others, antimalarial, antiviral, antitumor, and anti-inflammatory. Lycorine has been identified and characterized by thin layer chromatography, IR and NMR (1H and 13C NMR, COZY, HMBC, HSQC and NOESY). ⋯ To confirm these results, it is necessary to use qualitative techniques and methods, etc… We performed a virtual docking ligand-lycorine protein screening study to predict and characterize their mode of interaction with the LpxC receptor. Docking results have shown that lycorine can interact with target amino residues studied by hydrogen and metal-ion bonds. In addition, the ADME-Tox profile study has shown that lycorine is all in agreement, either with Lipinski's critics or with the toxicity standards.
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Microbial pathogenesis · Dec 2017
Attenuation of Pseudomonas aeruginosa quorum sensing, virulence and biofilm formation by extracts of Andrographis paniculata.
Quorum-sensing (QS) is known to play an essential role in regulation of virulence factors and toxins during Pseudomonas aeruginosa infection which may frequently cause antibiotic resistance and hostile outcomes of inflammatory injury. Therefore, it is an urgent need to search for a novel agent with low risk of resistance development that can target QS and inflammatory damage prevention as well. Andrographis paniculata, a herbaceous plant under the family Acanthaceae, native to Asian countries and also cultivated in Scandinavia and some parts of Europe, has a strong traditional usage with its known antibacterial, anti-inflammatory, antipyretic, antiviral and antioxidant properties. ⋯ The chloroform extract, which was found to be more effective, decreased expression of lasI, lasR, rhlI and rhlR by 61%, 75%, 41%, and 44%, respectively. Moreover, chloroform extract decreased activation of p-p38 and p-ERK1/2 expression levels in MAPK signal pathways in P. aeruginosa infected macrophage cells. As the present study demonstrates that A. paniculata extracts inhibit QS in P. aeruginosa and exhibit anti-inflammatory activities, therefore it represents itself as a prospective therapeutic agent against P. aeruginosa infection.
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Microbial pathogenesis · Nov 2017
Inhibition of quorum sensing related virulence factors of Pseudomonas aeruginosa by pyridoxal lactohydrazone.
Pseudomonas aeruginosa quorum sensing (QS) system is a cell to cell signaling mechanism that regulates virulence factors and pathogenicity. Therefore, the QS system in P. aeruginosa may be an important target for pharmacological intervention. The present study aimed to investigate the effects of sub-MIC concentrations of (S,E)-2-hydroxy-N-(3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)propane hydrazide (pyridoxal lactohydrazone) against P. aeruginosa QS related virulence factors. ⋯ Because of quorum sensing is a promising target for anti-virulence therapy and also important role of LasR regulatory protein in the initiation of P. aeruginosa QS system, we carried out molecular docking for understanding the interactions of pyridoxal lactohydrazone with the LasR receptor. The results of docking study suggested that the pyridoxal lactohydrazone has potential to inhibit the LasR protein. The results indicated that sub-MIC concentrations of this compound exhibited inhibitory effect on P. aeruginosa QS related virulence factors.
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Microbial pathogenesis · Oct 2017
Inhibition of quorum sensing-controlled biofilm formation in Pseudomonas aeruginosa by quorum-sensing inhibitors.
Antimicrobial therapy against extensively drug-resistant (XDR) P. aeruginosa biofilms is less efficient compared to the treatment of equal bacterial counts of free-floating planktonic cells, which has become a serious threat in hospital environment. P. aeruginosa regulate their cooperative activities and physiological processes through a cell to cell chemical communication process called Quorum sensing (QS). This attracted our interest to synthesize, and to chemically characterize two anti-QS compounds, N-(4-{4-fluoroanilno} butanoyl) -l-homoserine lactone (FABHL) and N-(4-{4-chlororoanilno} butanoyl) -l-homoserine lactone (CABHL) to inhibit biofilm formation via disabling the QS circuits. ⋯ Hence, the synthesized compounds have the potential to serve as a potent anti-biofilm agent via disabling the QS systems. Lethality of FABHL and CABHL against PBMCs was assessed by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphynyl tetrazolium bromide (MTT) assay. Cell viability was observed for both the compounds.